Precision forming of metal



Oct- 3 1950 T. G. JUNGERSEN Erm. 2,524,057

PRECISION FORMING 0F METAL OGL 3,1950 T. G. JUNGERSEN ETAL 2,524,057

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\ 46 @lig 47 Mll m @iQ-5i@ www Patented Oct. 3, 1950 PRECISION FORMING OF METAL Thoger IGr. J ungersen and Thoger G. Jungersen, Jr., Summit, N. J.

Application July 18, 1946, Serial No. 684,450

3 Claims.

This invention relates to the precision forming of metal and more particularly to the precision forming of metal while it is in a hot plastic state and in a non-oxidizing atmosphere under the influence of pressure.

Prior to the instant invention relatively crude metal forming has been accomplished by machine forging, but forgings produced by prior processes have required considerable machining and finishing.

It is an object of the instant invention to teach a novel process of precision metal forming.

It is another object of the invention to provide a novel apparatus for the forming of metal with precision.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

Figure l is a fragmentary vertical sectional View with parts shown in elevation of an apparatus in accordance with the invention.

Fig. 2 is a view similar to Fig. l showing relative positionspf parts of the apparatus during various stages of operationthereof.

Fig. 3 is a view similar to Figs. 1 and 2 taken along line 3-3 of Fig. 2 and looking in the direction of the arrows, portions of the apparatus being in different operating positions from that shown in Fig. 2.

Referring to the drawings, a pellet of metal I is introduced into the ceramic loading tube II through the hatch I2 and comes to rest against the stop I3 which protrudes upwardly through the hole I4 formed in the underside of the ceramic tube I I. In this position the pellet I0 is raised to a temperature sufliciently high to cause it to become plastic by the induction heating coils I5. When this temperature has been induced into the pellet I Il, the stop I3 is caused to move downwardly by engagement of the bottom corner I6 of the plunger P with the roller II on the lever I8 which is normally held in a horizontal position by the tension spring I9, the stop element I3 being connected to the lever I8 by the U-shaped link 2U. With the stop element I3 in its depressed position, the hot plastic pellet I then falls into the die cavity 2| as shown in Figure 2.

Within the die cavity 2l is the die section 22 which cooperates with a die section 23 in the bottom of the plunger P to form an accurate die corresponding to the shape of the finished metal piece desired.

The base element 24 is incorporated into the frame of the machine and the rod 25 is adapted to slide therethrough; the element 26 is secured to the rod 25 and has portion 2l adapted to contact the head of the adjustment screw 28 which is secured to the element 29 which in turn is xed to the valve stem 30 which in turn is secured to the ball valve 3l so that when the Valve 3I is unseated from the valve seat 32 the space within the bell jar 33 is communicated to the atmosphere through the passageway 34. The compression spring 35 holds the valve 3l in its closed position when the head of the adjustment screw 28 is not in engagement with the portion 21 of the xed element 26.

The base element 24 is also provided with a passageway 3B leading from the space beneath the bell jar 33 to the conduit 3l which is connected to a vacuum pump, not shown.

The rod 33 is connected at its bottom 39 to the plunger P and the upper portion thereof is arranged in sealed relation with the opening through the top of the bell jar 33 and is further arranged so as to be capable of sliding through the opening 43 while the seal therethrough is maintained by the packing 4| and the packing nut 42. Above the bottom 39 of the rod 38 is the annular projection 43 which is adapted to engage the under side 44 of the top of the bell jar 33 when the rod 38 is in fully raised position.

In the operation of the device described above, with the rod 38 in its uppermost position as shown in Fig. 3 and with the bell jar 33 in raised position, the operator has access to the mold cavity between the mold section 22 and the mold section 23 for the removal of any already formed metal piece. A pellet Il) may then be inserted through the hatch I2 in the ceramic tube I I and it will come to rest against the stop element I3. The operator then causes the lowering of the rod 38 until it takes the position shown in dotted lines in Fig. 2 and in this position the bottom 45 is in sealing relation with the annular gasket 46 arranged on the top 41 of the element 24. Movement of the rod 38 to this position automatically cuts in the vacuum pump and when a sufcient vacuum has been produced beneath the bell jar 33, a vacuum responsive switch S associated with the suction line 31 closes the circuit to the induction coil I3 and when the pellet I0 has been heated to a sufliciently high temperature to cause it to become plastic which, for a given size pellet of a given material, requires a predetermined xed time, a timing element T then permits the rod 38 to be further lowered until it takes the position shown in broken lines in Fig. 2 whereupon the corner I6 of the plunger P will engage the roller I1 and depress the stop element I3 to permit the pellet l in plastic state to fall into the cavity 2|. At this time the plunger is still moving downwardly and continues to move downwardly until it takes the position shown in Fig. 1 and forms the pellet l0 into the finished metal piece 48. The rod 38 is then caused to rise and the rod is caused to rise until element 26 Xed to the rod 25 engages the adjusting screw 28 and against the action of the spring 35 the valve 3| is opened permitting the atmosphere to enter the space beneath the bell jar 33. Thereupon the operator effects the continued raising of the rod 38 and the stop element I3 again enters through the opening I4 in the ceramic tube Il and takes the position shown in dotted lines in Fig. l. Further movement of the rod 38 in an upward direction then causes the bell jar 33 to raise as shown in Fig. 3 and the operator may remove from the raised die section 22 the nished metal piece 48 which will have been precision formed.

Instead of the operator removing the finished metal piece 48 as described, conventional knockout pins may be provided.

If desired, the atmosphere beneath the bell ,jar when it is in sealed relation with the top 41 of the element 24 may be filled with a nonoxidizing atmosphere such as nitrogen gas through the line 31 after the atmosphere has been removed from beneath the bell jar 33 by the vacuum pump.

Movement of the rod 38 may be hydraulically controlled and operated. With the utilization of the device in the process above described, the finished metal pieces will be accurate in dimension and precision parts may be thus formed to close tolerances without the necessity of further machining of surfaces or removal of ashings and gates or the like. The metals of which the nal precision piece is to be made may be selected from either the softer metals or harder metals such as the tougher steels.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and 4 therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. In an apparatus for precision forming metal pieces, means for holding a metal pellet of predetermined size while it is being heated, a die having a die cavity, means for creating a, nonoxidizing ambient about said pellet while it is being held and in said die cavity, means for heating said metal pellet until it reaches a plastic state, means for causing the introduction of said metal pellet in a plastic state into said die cavity, means for squeezing said metal pellet into said die cavity until it takes the shape of said die cavity, said last two means being interconnected so that said pellet is introduced into the die cavity prior to the operation of said means for squeezing said pellet.

2. The structure recited in claim 1, said means for creating a non-oxidizing ambient including a vacuum pump and bell jar, said holding means including a ceramic tube passing through in sealed relation to said bell jar, said heating means including an induction heating coil.

3. The structure recited in claim 1, and means responsive to the creation of said non-oxidizing ambient for rendering effective said heating means.

THOGER G. JUNGERSEN. THOGER G. JUNGERSEN, JR.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,380,250 Reymond May 31, 1921 1,822,939 Stout Sept. 15, 1931 2,089,030 Krathy Aug. 3, 1937 2,362,701 Kolhring Nov. 14, 1944 FOREIGN PATENTS Number Country Date 555,025 Great Britain July 29, 1943 

